Strap tensioning tool



Nmn W WW A. E. ADAMswM STRAP TENSIONING TOOL mzmw Filed Sept. 12, 1938 2 Sheets-$heet 1 ANDREW E Arman 15cm 5:513 W @Hlmmm No'v. W, 1940. A. E. ADAMSON 2 3 STRAP TE NS IONING TOOL Filed Sept. 12, 1938 2 Sheets-Sheet 2 ANDF? EW El- ADAMsoN M f' W Patented Nov. 19, 1940 UNITED STATES PATENT OFFICE STRAP TEN SIGNING TOOL Application September 12, 1938, Serial No. 229,639

3 Claims.

This invention relates to improvements in strap stretching devices and more particularly to a tool for engaging and stretching or drawing taut a reach of a metal strap or other flexible member extending about a box, bale or other object to be bound by such strap or member. The tool is particularly useful in tensioning the strap preparatory to the application of sealing means to overlapped portions thereof and has as its principal feature a unitary rotatable element for engagement with both the overlapped reach of the strap and a bearing surface of another portion of the strap which element may be rotated incrementally by oscillation of an operating lever whereby the application of such tensioned and sealed straps may be readily and expeditiously accomplished.

Accordingly, the primary object of the invention is the provision of a tool for the purpose described which is simple in design, economical to construct, and which is capable of performing its function with less skill required on the part of the user.

The invention consists, essentially, in the combination of a strap engaging and tensioning drum rotatably carried by a lever, a ratchet connection being provided between the drum and lever whereby the lever drives the drum when it is moved in one direction but which enables the lever to be moved in the opposite direction without movement of the drum. This arrangement enables the tool to be used in various positions in which the tool would be useless if the ratchet connection were not provided and therefore another object of the invention is the provision of a tool of the type described which is capable of more universal use than any comparable tool heretofore devised.

Another object of the invention is to provide a tool of such design that it may be assembled either for right hand or left hand manipulation while utilizing identical parts in both instances thus effecting economies in the construction of the various tools.

These and other objects and advantages of the invention will become apparent from a consideration of the drawings and the following detailed specification wherein there is specifically disclosed a preferred embodiment of the invention.

In the drawings:

Figure 1 is a plan view of a tool constructed in accordance with my invention; The tool is shown in operative position in relation to a strap extending about a box to be bound;

Figure 2 is a side view of the assembly of Figure 1;

Figure 3 is a sectional view, taken along the line 3-4 of Figure 1;

Figure 4 is a plan view of a tool assembled for left handed manipulation;

Figure 5 is a side view, partly in section, of the tool of Figure 4; and

Figure 6 illustrates a representative use to which the tool of my invention may be put.

Referring to Figures 1, 2 and 3 which illustrate a tool assembled for right handed manipulation in the manner shown in the drawings, the tool consists generally of the strap engaging and tensioning drum l8 carried by and rotatably moved by the lever I 0. The latter is provided with a forked end ii, an offset portion l2 and a hand grip extension i3. Forks H are provided with axially aligned bores to receive the shaft l9 which supports the drum l8 and which is preferably integral therewith. The central portion of shaft 19 extending between the forks ii is squared at 20, as shown in Figure 3, to fit within the squared opening through the ratchet wheel 2! which in assembled position of the parts is received between the forks II. The parts described are assembled by first positioning the ratchet wheel 2i between the forks and then passing the shaft l9 through the forks II and ratchet wheel 2!. To secure the parts in assembled relation a cap 26 is fitted over the end of shaft 19 and is suitably secured thereto by the pin 21.

Ratchet wheel 2! is engaged by a pawl 22 which is slidably received within a bore l4 extending axially along member II] from between the forks H. Pawl 22 has a flattened surface 24 which coacts with the inner end surface of a set screw 23 to prevent rotation of the pawl. For reasons to be later described identical threaded bores I 5 and it extend through opposite walls of the bore l4 and into one of these threaded bores the set screw 23 is inserted. The coil spring 25 positioned in bore l4 behind pawl 22 resiliently urges the latter into engagement with the ratchet wheel 2 l.

Tensioning drum i8 is provided with a diametrically extending slot 28 adapted to receive a portion of the strap or band which is to be tensioned about the object to be bound. The peripheral surface of drum I8 is machine cut to provide a serrated surface having a multiplicity of sharp projections extending outwardly from the surface. Drum it is then hardened to increase its wear-resisting qualities.

The operation of the tool described above is illustrated in Figures 1 and 2 which show a box 36 having a band or strap 3| extending thereabout and overlapped at 32 where a seal or other means of clamping the overlapped reaches together may be applied. The outer overlapped reach extends outwardly from the box to provide a portion 33 which is adapted to be received within the slot 28 of drum I B. By positioning drum I8 so that it engages box 38 or strap 3I below the box corner adjacent 32 rotation of the drum in a clockwise direction, as viewed in Figure 2, will result in an outward and downward pull on the strap end 33 thus tensioning the strap about the box. As the tension increases the drum I8 is brought into tighter pressure engagement with the box or strap 3I thus preventing slipping of the drum relative to the box and strap. If it is found that sufficient rotation of drum I8 to properly tension the strap can not be accomplished in one sweep of the handle I3 the handle may be returned towards its initial position without consequent movement of drum I8 as the ratchet connection 2I-22 enables this to be accomplished. The handle I3 may be then again moved to further rotate drum I8 in a counter-clockwise direction thus further taking up the slack in the strap or band and further tensioning same.

Offset I2 positions the hand grip portion I3 of the lever II] in the plane of encirclement of the strap 3 I thereby eliminating any tendency of the tool to twist or cant when pressure is being applied thereto. By extending the slot 28 to the outer face of drum I8, the strap portion 33 may be inserted in the slot simply by moving the drum laterally of the portion. This enables the tool to be applied to the strap by the use of but one hand of the operator and as the tool is otherwise designed for single handed operation it may be rapidly and skillfully manipulated. In this connection it is pointed out that the tool as a whole may be used as a hammer, the cap 26 serving as the striking member. A particular use to which the tool described may be advantageously put is the tensioning of straps about low objects as the box 30 of Figure 2. By reason of the fact that the floor or upper surface or other support, represented by 35 in Figure 2, limits the sweep of the handle I3, the ratchet arrangement described is particularly desirable as it enables the handle I3 to be oscillated without requiring any reversal of movement of the tensioning drum I8.

Figures 4 and 5 illustrate a tool assembled for left handed manipulation in the same operation as shown exemplarily in Figures 1 and 2. In the use of these tools it is desirable for various rea-* sons to have the drum I8 extend toward the front of the operator and therefore by the terms right handed and left handed is meant the hand by which the user would normally grip the tool. The tool of Figures 4 and 5 utilizes precisely the same parts as the tool of the first described figures, the only difference between the tools being a difierence in the assembly of the parts. The ratchet wheel 2I and pawl 22 are reversed, which reversal of the latter necessitates the positioning of the set screw 23 in threaded bore I5 instead of as in I6 in the. first described figures. It can thus be seen that by the use of my design substantial economies can be effected in the construction of the parts and assembly of the tools.

Figure 6 illustrates another representative use to which the tool of my invention may be put and shows a coil of material 38 which it is desired to bind with the straps or bands 3I. Inasmuch as it is desirable to have the broken or cut off end of the straps within the coil so as to lessen danger of injury to persons handling the coil the strap must necessarily be tensioned by positioning the tool within the coil. The design of the tool of this invention enables the same to be so positioned and in this use the drum I8 engages the end portion of the strap and tracks down the inner surface of the coil to tension the strap. The ratchet connection above defined enables rotation of the drum sufficient to properly tension the strap to be effected regardless of the extent of space available for movement of the handle I3. Upon completion of the tensioning operation. a seal, as shown at 40, may be applied to overlapped portions of the strap to hold the strap in tensioned condition.

The above specifically described embodiment of my invention should be considered as illustrative only as obviously many changes may be made therein without departing from the spirit or scope of my invention, the extent of which is indicated in the appended claims. It should be understood that the tools herein described are capable of other and further uses than those specifically mentioned. In use the handle of the tool may' be either pulled towards or pushed away from the operator or pulled up or pushed down by the operator during the tensioning movement of the handle depending on the particular situation in each case.

What I claim is:

1. A strap tensioning tool comprising a lever having an offset portion and a forked end adjacent said portion, a strap tensioning drum having means to engage the portion of a metal binding strap and a serrated peripheral surface to engage a tool bearing surface rotatably sup-ported and carried by said lever, said drum being carried immediately adjacent the outer surface of one of the forks of said forked end on a shaft journalled in aligned apertures in said forked end, a ratchet wheel keyed to said shaft intermediate said forks, a spring pressed pawl carried by said lever and adapted to engage said ratchet wheel to rotate the same and consequently the drum upon pivotal movement of the lever in one direction and to override said ratchet wheel upon pivotal movement of the lever in the opposite direction, the diameters of said ratchet wheel and said forked end being less than the diameter of said drum.

2. A device according to claim 1 further characmrized in that said shaft extends beyond the outer surface of the other of said forks, and a cap member secured to said projecting shaft end, said cap member being positioned immediately adjacent said other fork.

3. A strap tensioning tool comprising a lever having an offset end, a forked end adjacent said offset, a longitudinal bore in said lever extending from between the forks of said forked end, diametrically opposite tapped apertures in the side wall of said bore, a strap tensioning drum having a shaft extending through aligned apertures in said forked end, a ratchet wheel keyed to said shaft between said forks, said drum being provided with means to engage a portion of a strap and having a serrated peripheral surface, to engage a tool bearing surface, the diameters of said ratchet wheel and said forked end being less than the diameter of said drum, a coil spring in said bore, a pawl in said bore and engaging said wheel, said pawl being provided with a flattened portion extending for a portion of its length and a set screw in one of said tapped apertures extending substantially to said flattened portion.

ANDREW E. ADAMSON. 

